North Korea fired an intercontinental ballistic missile (ICBM) early Wednesday morning, the Pentagon has said.

According to South Korea’s Joint Chiefs of Staff (JOC), the launch came from the South Pyongan province at 3:17 a.m.

Both South Korean and U.S. authorities are currently analyzing the trajectory, the JOC added. The Pentagon stated that the missile came from a mobile launcher.

The Pentagon’s initial assessment found that the ICBM traveled roughly 1,000km at an altitude of 4,500km before splashing down into the Sea of Japan.

“This is the highest performance we’ve seen in North Korea’s ICBM to date,” Shea Cotton, research associate at the James Martin Center for Nonproliferation Studies, said on Twitter.

The Japanese Prime Minister’s office said the North Korean missile appeared to fly for 50 minutes.

“The missile flew over Japan’s northern main island of Hokkaido and fell into the Pacific Ocean,” Japanese news outlet NHK reports.

Experts say the rare nighttime launch is intended to simulate a real-world military scenario.

The South Korean military staged a “precision strike” missile exercise in response to Pyongyang’s launch.

President Donald Trump addressed the media at 3:30 p.m. EST to discuss the DPRK’s actions.

The North Korean test follows reports out of Japan and the U.S. that said a missile test could come within days after radio signals and radar activity were detected at a North Korean missile base.

Pyongyang’s last missile launch was more than two months prior on Sept. 15. The 75 day pause was the longest seen in 2017, which has produced 20 missile tests in total.

South Korea’s unification minister had warned Tuesday that North Korea’s nuclear program could be completed by as early as next year.

“North Korea has been developing its nuclear weapons at a faster-than-expected pace. We cannot rule out the possibility that North Korea could announce its completion of a clear force within one year,” Cho Myoung-gyon said.